How prevalent are polyps?

Colorectal CA 

• Most (>95%) CRC arise in adenomatous polyps

Risk of Malignancy

• 5-9 mm 1%
• 10-20 mm 4-10%
• >20 mm 25-40%
• <10 mm polyp-invasive ca: 10 years

Adenomatous: Benign glandular tumor

Prevalence

• 25% of people by age 50
• 50-60% of people by age 80
• Villous=10x Tubular malignant potential